Halep was caught off guard early on by Duan's big hitting but the world No.1 turned the match on its head by breaking Duan twice in the second set to force the match into the decider.

Troubled by a thigh problem late in the match, Duan took a medical timeout and returned for the decider with her left thigh heavily strapped.

Halep, who battled past Duan in their previous meeting in Eastbourne last year, took advantage as Duan struggled to find her rhythm and raced to a 5-0 lead. She then subdued a late fightback to seal the win in 97 minutes.

"I knew that she is playing really hard and hitting every ball. I knew I had to be strong on my legs," Halep said.

"After the first set I was thinking I have to find rhythm, to stay closer to the baseline and open the court better, which I did... It was a very tough match."